The present invention relates to video/audio quality of service, and more particularly to a method of quantifying perceptual information and entropy in order to solve various video/audio quality of service problems.
In communication systems, whether video, audio or both, the quality of the video/audio is measured in several ways. Quality implies subjective quality, a function of perceptual response to a signal. One method of quality measurement is a signal subjective quality degradation measurement that uses a reduced reference, i.e. a single number or compact set, such as that described in U.S. Pat. No. 6,246,435 issued Jun. 12, 2001 to Kamalesh Patel entitled “In-Service Realtime Picture Quality Analysis.” Another method uses a single-ended signal quality measurement where there is no reference, such as that described in pending U.S. patent application Ser. No. 09/152,495 filed Sep. 10, 1998 by Bozidar Janko et al entitled “Picture Quality Measurements Using Blockiness.” Also an upper quality bound of a communication channel is often desired to determine if perceptually transparent (perfect) transmission is possible over the communication channel with known bandwidth and, if not, what level of perceptual degradation may be expected. Finally for a band-limited channel or where a limited number of bits represent a signal, the optimum perceptual encoding is desired to minimize the perceptual difference between the original and encoded signals similar to that described in pending U.S. patent application Ser. No. 09/369,234 filed Aug. 5, 1999 by Stephen Maurer entitled “Maximizing Usable Bandwidth in Systems Carrying Compressed Digital Signals.”
What is desired is a method for estimating/quantifying the minimum theoretical bit rate required to transmit video or audio signals over a communications channel, which facilitates improving existing communications channel quality measurements to provide more accurate quality estimates.